Method for making chlorohydrins

ABSTRACT

Methods and systems for the preparation of chlorohydrins are described herein. The methods and systems incorporate the novel use of a high shear device to promote dispersion and solubility of olefins into the chlorinating phase. The high shear device may allow for lower reaction temperatures and pressures and may also reduce chlorination time.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional application of U.S. patent applicationSer. No. 12/143,492, filed Jun. 20, 2008, which claims the benefit under35 U.S.C. § 119(e) of U.S. Provisional Patent Application No.60/946,487, filed Jun. 27, 2007. The disclosure of said applications arehereby incorporated herein by reference.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not Applicable.

BACKGROUND

1. Field of the Invention

This invention relates generally to the field of chemical reactions.More specifically, the invention relates to methods of makingchlorohydrins incorporating high shear mixing.

2. Background of the Invention

Chlorohydrins are useful as intermediates in producing variouscompounds. For example, propylene chlorohydrin and butylene chlorohydrinare used in producing propylene oxide and butylene oxide, respectively.

Various processes are known for the production of chlorohydrins. Forexample, olefin chlorohydrins are typically prepared by reacting anolefin with chlorine in the presence of water. This process is believedto occur by means of an intermediate cyclic chloronium ion which reactswith the water to form an olefin chlorohydrin. The olefin may be onecontaining from 8 to about 30 carbon atoms. However, the process alsoconcurrently forms undesirable dichloride byproducts when aqueouschloride ions react with the cyclic chloronium ions. Significant yieldlosses are typically suffered and the byproducts must be separated fromthe desired olefin chlorohydrin, an operation that adds to the cost ofmaking the chlorohydrin. Alternatively, the process described above mayinclude a water immiscible solvent. Therefore, the reaction would entailthe addition of hypochlorous acid to a long chain olefin in the presenceof water in a water immiscible solvent. Suitable solvents includedecane, chloroform and petroleum ether.

Other processes for producing chlorohydrins involve reacting olefinswith hypochlorous acid, wherein the process requires preliminarilyacidifying the olefin with gaseous hydrochloric acid and carrying outthe process at a pH of between 2 to 7, and preferably between 5 to 6.Another method of making chlorohydrins involves preparing hypochlorousacid by reacting chlorine and water in the presence of alkaline earthmetal hydroxides (maintaining a pH below 7.0), then, reacting thehypochlorous acid mixture with a vinyl group-containing compound.Alternatively the preparation of chlorohydrin may be achieved byreaction of olephins with trichloroisocyanuric acid in alcohols, aceticacid or aqueous acetone.

Various other methods of forming chlorohydrins are also well known suchas reacting olefins with t-butyl hypochlorite or hypochlorous acidsubstantially free of chloride ions. However, these methods typicallyeither result in the production of numerous byproducts or requirevarious, costly processing steps or long reaction times, thus hinderingthe commercial viability of the methods. For these reasons, thereremains a need for a process for producing chlorohydrin that iseffective and results in high yields of the desired product.

In light of the above, it is apparent that research has been focused ondifferent reaction pathways in producing chlorohydrins. However, none ofthese methods discuss improving the solubility and mass transfer of thereactants through improved mixing.

Consequently, there is a need for accelerated methods for makingchlorohydrins by improving the mixing of olefins into the liquidchlorinating phase.

BRIEF SUMMARY

Methods and systems for the preparation of chlorohydrins are describedherein. The methods and systems incorporate the novel use of a highshear device to promote dispersion and solubility of olefins into thechlorinating phase. The high shear device may allow for lower reactiontemperatures and pressures and may also reduce chlorination time.Further advantages and aspects of the disclosed methods and system aredescribed below.

In an embodiment, a method of making a chlorohydrin comprises contactingan olefin with a chlorinating agent. In an embodiment the liquid is anaqueous solution, a hypochlorous acid solution, an aqueous hypochloritesolution or chlorine dissolved in H₂O and the gas comprised of an olefinwhich is reactive under the conditions of mixing with one or morecomponents of the liquid to form reaction products including the desiredolefin chlorohydrin product. The method also comprises flowing theolefin and the chorinating agent through a high shear device so as toform dispersion with bubbles less than about 1 μm and form achlorohydrin.

In an embodiment, a system for making a chlorohydrin comprises at leastone high shear device configured for chlorinating an olefin. The highshear device comprises a rotor and a stator. The rotor and the statorare separated by a shear gap in the range of from about 0.02 mm to about5 mm. The shear gap is a minimum distance between the rotor and thestator. The high shear device is capable of producing a tip speed of theat least one rotor of greater than about 23 m/s (4,500 ft/min). Inaddition, the system comprises a pump configured for delivering a liquidstream comprising liquid phase to the high shear device.

The foregoing has outlined rather broadly the features and technicaladvantages of the present invention in order that the detaileddescription of the invention that follows may be better understood.Additional features and advantages of the invention will be describedhereinafter that form the subject of the claims of the invention. Itshould be appreciated by those skilled in the art that the conceptionand the specific embodiments disclosed may be readily utilized as abasis for modifying or designing other structures for carrying out thesame purposes of the present invention. It should also be realized bythose skilled in the art that such equivalent constructions do notdepart from the spirit and scope of the invention as set forth in theappended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

For a detailed description of the preferred embodiments of theinvention, reference will now be made to the accompanying drawings inwhich:

FIG. 1 illustrates a general flow diagram of an embodiment of a processof making chlorohydrins using a high shear device.

FIG. 2 illustrates a longitudinal cross-section view of a multi-stagehigh shear device, as employed in an embodiment of the system of FIG. 1.

NOTATION AND NOMENCLATURE

Certain terms are used throughout the following description and claimsto refer to particular system components. This document does not intendto distinguish between components that differ in name but not function.

In the following discussion and in the claims, the terms “including” and“comprising” are used in an open-ended fashion, and thus should beinterpreted to mean “including, but not limited to . . . ”.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The disclosed methods and systems for the chlorination of an olefinemploy a high shear mechanical device to provide rapid contact andmixing of the olefin gas and chlorinating agent in a controlledenvironment in the reactor/mixer device. The term “olefin gas” as usedherein includes both substantially olefin gas as well as gaseousmixtures containing olefin. In particular, embodiments of the systemsand methods may be used in the production of chlorohydrins from thechlorination of olefins in water. Preferably, the method comprises aheterogeneous phase reaction of a chlorine species in liquid phase withan olefin gas. The high shear device reduces the mass transferlimitations on the reaction and thus increases the overall reactionrate.

Chemical reactions involving liquids, gases and solids rely on the lawsof kinetics that involve time, temperature, and pressure to define therate of reactions. In cases where it is desirable to react two (or more)raw materials of different phases (e.g. solid and liquid; liquid andgas; solid, liquid and gas), one of the limiting factors in controllingthe rate of reaction involves the contact time of the reactants. As usedherein, “multi-phase” refers to a reaction involving reactions with twoor more different phases. In the case of heterogeneously catalyzedreactions there is the additional rate limiting factor of having thereacted products removed from the surface of the catalyst to enable thecatalyst to catalyze further reactants.

The chlorination of olefins to produce chlorohydrin is a multiphasereaction. During the multiphase reaction, the phases separatespontaneously. The presently disclosed method and system whereby the twophases are intimately mixed to form an emulsion enhances contact surfacebetween the reaction components, thus enhancing the reaction.

The pH of the reaction may have a direct impact on the reaction rate andthus the olefin conversion. The pH employed may vary depending on thechlorines present in the aqueous phase. The maximum pH is about 8. Whenthe aqueous phase contains free chloride ions and molecular chlorine,the pH should not be below 4.5. When an essentially chloride andchlorine-free aqueous solution is employed herein, the pH can range aslow as 1. The process described here in comprises an aqueous phasehaving a pH ranging from about 2 to about 8. Chlorohydrin yield isparticularly good in low olefin conversion when an aqueous phase of pHof about 6 is employed.

In conventional reactors, contact time for the reactants and/or catalystis often controlled by mixing which provides contact with two or morereactants involved in a chemical reaction. Embodiments of the disclosedmethod comprise an external high shear device to decrease mass transferlimitations and thereby more closely approach kinetic limitations. Whenreaction rates are accelerated, residence times may be decreased,thereby increasing obtainable throughput. Alternatively, where thecurrent yield is acceptable, decreasing the required residence timeallows for the use of lower temperatures and/or pressures thanconventional processes. Furthermore, in homogeneous reactions, thedisclosed process could be used to provide for uniform temperaturedistribution within the reactor thereby minimizing potential sidereactions.

System for Production of Chlorohydrin. A high shear chlorohydrinproduction system will now be described in relation to FIG. 1, which isa process flow diagram of an embodiment of a high shear system (HSS) 100for the production of chlorohydrin via reacting a chlorinating agentwith olefins in a gas-liquid phase reaction. The basic components of arepresentative system include external high shear device (HSD) 140,vessel 110, pump 105 and fluidized or fixed bed 142. As shown in FIG. 1,the high shear device is located external to vessel/reactor 110. Each ofthese components is further described in more detail below. Line 121 isconnected to pump 105 for introducing reactant. Line 113 connects pump105 to HSD 140, line 118 connects HSD 140 to fluidized or fixed bed 142and line 119 connects bed to vessel 110. Line 122 is connected to line113 for introducing an oxygen-containing gas (e.g., O₂ or air). Line 117is connected to vessel 110 for removal of unreacted vapor, and otherreaction gases. High shear devices (HSDs) such as a high shear device,or high shear mill, are generally divided into classes based upon theirability to mix fluids. Mixing is the process of reducing the size ofinhomogeneous species or particles within the fluid. One metric for thedegree or thoroughness of mixing is the energy density per unit volumethat the mixing device generates to disrupt the fluid particles. Theclasses are distinguished based on delivered energy density. There arethree classes of industrial mixers having sufficient energy density toconsistently produce mixtures or emulsions with particle or bubble sizesin the range of 0 to 50 microns. High shear mechanical devices includehomogenizers as well as colloid mills.

Homogenization valve systems are typically classified as high energydevices. Fluid to be processed is pumped under very high pressurethrough a narrow-gap valve into a lower pressure environment. Thepressure gradients across the valve and the resulting turbulence andcavitations act to break-up any particles in the fluid. These valvesystems are most commonly used in milk homogenization and can yieldaverage particle size range from about 0.01 μm to about 1 μm. At theother end of the spectrum are high shear mixer systems classified as lowenergy devices. These systems usually have paddles or fluid rotors thatturn at high speed in a reservoir of fluid to be processed, which inmany of the more common applications is a food product. These systemsare usually used when average particle, or bubble, sizes of greater than20 microns are acceptable in the processed fluid.

Between low energy-high shear mixers and homogenization valve systems,in terms of the mixing energy density delivered to the fluid, arecolloid mills, which are classified as intermediate energy devices. Thetypical colloid mill configuration includes a conical or disk rotor thatis separated from a complementary, liquid-cooled stator by aclosely-controlled rotor-stator gap, which is maybe between 0.025 mm and10.0 mm. Rotors are usually driven by an electric motor through a directdrive or belt mechanism. Many colloid mills, with proper adjustment, canachieve average particle, or bubble, sizes of about 0.01 μm to about 25μm in the processed fluid. These capabilities render colloid millsappropriate for a variety of applications including colloid andoil/water-based emulsion processing such as that required for cosmetics,mayonnaise, silicone/silver amalgam formation, or roofing-tar mixing.

An approximation of energy input into the fluid (kW/L/min) can be madeby measuring the motor energy (kW) and fluid output (L/min). Inembodiments, the energy expenditure of a high shear device is greaterthan 1000 W/m³. In embodiments, the energy expenditure is in the rangeof from about 3000 W/m³ to about 7500 W/m³. The shear rate generated ina high shear device may be greater than 20,000 s⁻¹. In embodiments, theshear rate generated is in the range of from 20,000 s⁻¹ to 100,000 s⁻¹.

Tip speed is the velocity (m/sec) associated with the end of one or morerevolving elements that is transmitting energy to the reactants. Tipspeed, for a rotating element, is the circumferential distance traveledby the tip of the rotor per unit of time, and is generally defined bythe equation V (m/sec)=π·D·n, where V is the tip speed, D is thediameter of the rotor, in meters, and n is the rotational speed of therotor, in revolutions per second. Tip speed is thus a function of therotor diameter and the rotation rate. Also, tip speed may be calculatedby multiplying the circumferential distance transcribed by the rotortip, 2πR, where R is the radius of the rotor (meters, for example) timesthe frequency of revolution (for example revolutions (meters, forexample) times the frequency of revolution (for example revolutions perminute, rpm).

For colloid mills, typical tip speeds are in excess of 23 m/sec (4500ft/min) and can exceed 40 m/sec (7900 ft/min). For the purpose of thepresent disclosure the term ‘high shear’ refers to mechanicalrotor-stator devices, such as mills or mixers, that are capable of tipspeeds in excess of 5 m/sec (1000 ft/min) and require an externalmechanically driven power device to drive energy into the stream ofproducts to be reacted. A high shear device combines high tip speedswith a very small shear gap to produce significant friction on thematerial being processed. Accordingly, a local pressure in the range ofabout 1000 MPa (about 145,000 psi) to about 1050 MPa (152,300 psi) andelevated temperatures at the tip of the shear mixer are produced duringoperation. In certain embodiments, the local pressure is at least about1034 MPa (about 150,000 psi).

Referring now to FIG. 2, there is presented a schematic diagram of ahigh shear device 200. High shear device 200 comprises at least onerotor-stator combination. The rotor-stator combinations may also beknown as generators 220, 230, 240 or stages without limitation. The highshear device 200 comprises at least two generators, and most preferably,the high shear device comprises at least three generators.

The first generator 220 comprises rotor 222 and stator 227. The secondgenerator 230 comprises rotor 223, and stator 228; the third generatorcomprises rotor 224 and stator 229. For each generator 220, 230, 240 therotor is rotatably driven by input 250. The generators 220, 230, 240rotate about axis 260 in rotational direction 265. Stator 227 is fixablycoupled to the high shear device wall 255.

The generators include gaps between the rotor and the stator. The firstgenerator 220 comprises a first gap 225; the second generator 230comprises a second gap 235; and the third generator 240 comprises athird gap 245. The gaps 225, 235, 245 are between about 0.025 mm (0.01in) and 10.0 mm (0.4 in) wide. Alternatively, the process comprisesutilization of a high shear device 200 wherein the gaps 225, 235, 245are between about 0.5 mm (0.02 in) and about 2.5 mm (0.1 in). In certaininstances the gap is maintained at about 1.5 mm (0.06 in).Alternatively, the gaps 225, 235, 245 are different between generators220, 230, 240. In certain instances, the gap 225 for the first generator220 is greater than about the gap 235 for the second generator 230,which is greater than about the gap 245 for the third generator 240.

Additionally, the width of the gaps 225, 235, 245 may comprise a coarse,medium, fine, and super-fine characterization. Rotors 222, 223, and 224and stators 227, 228, and 229 may be toothed designs. Each generator maycomprise two or more sets of rotor-stator teeth, as known in the art.Rotors 222, 223, and 224 may comprise a number of rotor teethcircumferentially spaced about the circumference of each rotor. Stators227, 228, and 229 may comprise a number of stator teethcircumferentially spaced about the circumference of each stator. Therotor and the stator may be of any suitable size. In one embodiment, theinner diameter of the rotor is about 64 mm and the outer diameter of thestator is about 60 mm. In further embodiments, the rotor and stator mayhave alternate diameters in order to alter the tip speed and shearpressures. In certain embodiments, each of three stages is operated witha super-fine generator, comprising a gap of between about 0.025 mm andabout 3 mm. When a feed stream 205 including solid particles is to besent through high shear device 200, the appropriate gap width is firstselected for an appropriate reduction in particle size and increase inparticle surface area. In embodiments, this is beneficial for increasingcatalyst surface area by shearing and dispersing the particles.

High shear device 200 is fed a reaction mixture comprising the feedstream 205. Feed stream 205 comprises an emulsion of the dispersiblephase and the continuous phase. Emulsion refers to a liquefied mixturethat contains two distinguishable substances (or phases) that will notreadily mix and dissolve together. Most emulsions have a continuousphase (or matrix), which holds therein discontinuous droplets, bubbles,and/or particles of the other phase or substance. Emulsions may behighly viscous, such as slurries or pastes, or may be foams, with tinygas bubbles suspended in a liquid. As used herein, the term “emulsion”encompasses continuous phases comprising gas bubbles, continuous phasescomprising particles (e.g., solid catalyst), continuous phasescomprising droplets of a fluid that is substantially insoluble in thecontinuous phase, and combinations thereof.

Feed stream 205 may include a particulate solid catalyst component. Feedstream 205 is pumped through the generators 220, 230, 240, such thatproduct dispersion 210 is formed. In each generator, the rotors 222,223, 224 rotate at high speed relative to the fixed stators 227, 228,229. The rotation of the rotors pumps fluid, such as the feed stream205, between the outer surface of the rotor 222 and the inner surface ofthe stator 227 creating a localized high shear condition. The gaps 225,235, 245 generate high shear forces that process the feed stream 205.The high shear forces between the rotor and stator functions to processthe feed stream 205 to create the product dispersion 210. Each generator220, 230, 240 of the high shear device 200 has interchangeablerotor-stator combinations for producing a narrow distribution of thedesired bubble size, if feedstream 205 comprises a gas, or globule size,if feedstream 205 comprises a liquid, in the product dispersion 210.

The product dispersion 210 of gas particles, or bubbles, in a liquidcomprises an emulsion. In embodiments, the product dispersion 210 maycomprise a dispersion of a previously immiscible or insoluble gas,liquid or solid into the continuous phase. The product dispersion 210has an average gas particle, or bubble, size less than about 1.5 μm;preferably the bubbles are sub-micron in diameter. In certain instances,the average bubble size is in the range from about 1.0 μm to about 0.1μm. Alternatively, the average bubble size is less than about 400 nm(0.4 μm) and most preferably less than about 100 nm (0.1 μm).

The high shear device 200 produces a gas emulsion capable of remainingdispersed at atmospheric pressure for at least about 15 minutes. For thepurpose of this disclosure, an emulsion of gas particles, or bubbles, inthe dispersed phase in product dispersion 210 that are less than 1.5 μmin diameter may comprise a micro-foam. Not to be limited by a specifictheory, it is known in emulsion chemistry that sub-micron particles, orbubbles, dispersed in a liquid undergo movement primarily throughBrownian motion effects. The bubbles in the emulsion of productdispersion 210 created by the high shear device 200 may have greatermobility through boundary layers of solid catalyst particles, therebyfacilitating and accelerating the catalytic reaction through enhancedtransport of reactants.

The rotor is set to rotate at a speed commensurate with the diameter ofthe rotor and the desired tip speed as described hereinabove. Transportresistance is reduced by incorporation of high shear device 200 suchthat the velocity of the reaction is increased by at least about 5%.Alternatively, the high shear device 200 comprises a high shear colloidmill that serves as an accelerated rate reactor (ARR). The acceleratedrate reactor comprises a single stage dispersing chamber. Theaccelerated rate reactor comprises a multiple stage inline dispersercomprising at least 2 stages.

Selection of the high shear device 200 is dependent on throughputrequirements and desired particle or bubble size in the outletdispersion 210. In certain instances, high shear device 200 comprises aDispax Reactor® of IKA® Works, Inc. Wilmington, N.C. and APV NorthAmerica, Inc. Wilmington, Mass. Model DR 2000/4, for example, comprisesa belt drive, 4M generator, PTFE sealing ring, inlet flange 1″ sanitaryclamp, outlet flange ¾″ sanitary clamp, 2HP power, output speed of 7900rpm, flow capacity (water) approximately 300 l/h to approximately 700l/h (depending on generator), a tip speed of from 9.4 m/s to about 41m/s (about 1850 ft/min to about 8070 ft/min). Several alternative modelsare available having various inlet/outlet connections, horsepower,nominal tip speeds, output rpm, and nominal flow rate.

Without wishing to be limited to a particular theory, it is believedthat the level or degree of high shear mixing is sufficient to increaserates of mass transfer and may also produce localized non-idealconditions that enable reactions to occur that would not otherwise beexpected to occur based on Gibbs free energy predictions. Localized nonideal conditions are believed to occur within the high shear deviceresulting in increased temperatures and pressures with the mostsignificant increase believed to be in localized pressures. The increasein pressures and temperatures within the high shear device areinstantaneous and localized and quickly revert back to bulk or averagesystem conditions once exiting the high shear device. In some cases, thehigh shear device induces cavitation of sufficient intensity todissociate one or more of the reactants into free radicals, which mayintensify a chemical reaction or allow a reaction to take place at lessstringent conditions than might otherwise be required. Cavitation mayalso increase rates of transport processes by producing local turbulenceand liquid micro-circulation (acoustic streaming).

Vessel. Vessel or reactor 110 is any type of vessel in which amultiphase reaction can be propagated to carry out the above-describedconversion reaction(s). For instance, a continuous or semi-continuousstirred tank reactor, or one or more batch reactors may be employed inseries or in parallel. In some applications vessel 110 may be a towerreactor, and in others a tubular reactor or multi-tubular reactor. Acatalyst inlet line 115 may be connected to vessel 110 for receiving acatalyst solution or slurry during operation of the system.

Vessel 110 may include one or more of the following components: stirringsystem, heating and/or cooling capabilities, pressure measurementinstrumentation, temperature measurement instrumentation, one or moreinjection points, and level regulator (not shown), as are known in theart of reaction vessel design. For example, a stirring system mayinclude a motor driven mixer. A heating and/or cooling apparatus maycomprise, for example, a heat exchanger. Alternatively, as much of theconversion reaction may occur within HSD 140 in some embodiments, vessel110 may serve primarily as a storage vessel in some cases.

Heat Transfer Devices. In addition to the above-mentionedheating/cooling capabilities of vessel 110, other external or internalheat transfer devices for heating or cooling a process stream are alsocontemplated in variations of the embodiments illustrated in FIG. 1.Some suitable locations for one or more such heat transfer devices arebetween pump 105 and HSD 140, between HSD 140 and vessel 110, andbetween vessel 110 and pump 105 when system 100 is operated inmulti-pass mode. Some non-limiting examples of such heat transferdevices are shell, tube, plate, and coil heat exchangers, as are knownin the art.

Pumps. Pump 105 is configured for either continuous or semi-continuousoperation, and may be any suitable pumping device that is capable ofproviding greater than 2 atm pressure, preferably greater than 3 atmpressure, to allow controlled flow through HSD 140 and system 100. Forexample, a Roper Type 1 gear pump, Roper Pump Company (Commerce Ga.)Dayton Pressure Booster Pump Model 2P372E, Dayton Electric Co (Niles,Ill.) is one suitable pump. Preferably, all contact parts of pump 105are stainless steel, for example, 316 stainless steel. In embodiments,for example, wherein corrosive substances will be pumped (e.g. sulfuricacid) it may be desirable to have gold plated contact surfaces. In someembodiments of the system, pump 105 is capable of pressures greater thanabout 20 atm. In addition to pump 105, one or more additional, highpressure pump (not shown) may be included in the system illustrated inFIG. 1. For example, a booster pump, which may be similar to pump 105,may be included between HSD 140 and vessel 110 for boosting the pressureinto vessel 110.

Production of Chorohydrins. In operation for the chlorination ofolefins, respectively, a dispersible olefin gas stream is introducedinto system 100 via line 122, and combined in line 113 with a liquidstream to form a gas-liquid stream. The liquid stream includes achlorinating agent in aqueous phase (i.e. Cl₂ dissolved in water).Alternatively, the olefin gas may be fed directly into HSD 140, insteadof being combined with the liquid reactant (i.e., water) in line 113.Pump 105 is operated to pump the liquid reactant (water) through line121, and to build pressure and feed HSD 140, providing a controlled flowthroughout high shear (HSD) 140 and high shear system 100. Optionally, agaseous chlorinating agent such as chlorine gas may be fed into line 121through line 111. In such an embodiment, an additional high shear devicemay be incorporated to dissolve the gaseous chlorinating agent intosolution.

In a preferred embodiment, olefin gas 122 may continuously be fed intothe liquid stream 112 to form high shear feed stream 113 (e.g.gas-liquid stream). In high shear device 140, liquid (i.e. water),chlorinating agent, and the olefin vapor are highly dispersed such thatnanobubbles and/or microbubbles of olefin are formed for superiordissolution of olefin vapor into solution. Once dispersed, thedispersion may exit high shear device 140 at high shear outlet line 118.Stream 118 may optionally enter fluidized or fixed bed 142 in lieu of aslurry catalyst process. However, in a slurry catalyst embodiment, highshear outlet stream 118 may directly enter hydration reactor 110 forhydration. The reaction stream may be maintained at the specifiedreaction temperature, using cooling coils in the reactor 110 to maintainreaction temperature. Chlorination products (e.g. chlorohydrins) may bewithdrawn at product stream 116.

In an exemplary embodiment, the high shear device comprises a commercialdisperser such as IKA® model DR 2000/4, a high shear, three stagedispersing device configured with three rotors in combination withstators, aligned in series. The disperser is used to create thedispersion of olefins in the liquid medium comprising water (i.e., “thereactants”). The rotor/stator sets may be configured as illustrated inFIG. 2, for example. The combined reactants enter the high shear devicevia line 113 and enter a first stage rotor/stator combination havingcircumferentially spaced first stage shear openings. The coarsedispersion exiting the first stage enters the second rotor/stator stage,which has second stage shear openings. The reduced bubble-sizedispersion emerging from the second stage enters the third stagerotor/stator combination having third stage shear openings. Thedispersion exits the high shear device via line 118. In someembodiments, the shear rate increases stepwise longitudinally along thedirection of the flow. For example, in some embodiments, the shear ratein the first rotor/stator stage is greater than the shear rate insubsequent stage(s). In other embodiments, the shear rate issubstantially constant along the direction of the flow, with the stageor stages being the same. If the high shear device includes a PTFE seal,for example, the seal may be cooled using any suitable technique that isknown in the art. For example, the reactant stream flowing in line 113may be used to cool the seal and in so doing be preheated as desiredprior to entering the high shear device.

The rotor of HSD 140 is set to rotate at a speed commensurate with thediameter of the rotor and the desired tip speed. As described above, thehigh shear device (e.g., colloid mill) has either a fixed clearancebetween the stator and rotor or has adjustable clearance. HSD 140 servesto intimately mix the olefin vapor and the reactant liquid (i.e.,water). In some embodiments of the process, the transport resistance ofthe reactants is reduced by operation of the high shear device such thatthe velocity of the reaction (i.e. reaction rate) is increased bygreater than a factor of about 5. In some embodiments, the velocity ofthe reaction is increased by at least a factor of 10. In someembodiments, the velocity is increased by a factor in the range of about10 to about 100 fold. In some embodiments, HSD 140 delivers at least 300L/h with a power consumption of 1.5 kW at a nominal tip speed of atleast 4500 ft/min, and which may exceed 7900 ft/min (140 m/sec).Although measurement of instantaneous temperature and pressure at thetip of a rotating shear unit or revolving element in HSD 140 isdifficult, it is estimated that the localized temperature seen by theintimately mixed reactants may be in excess of 500° C. and at pressuresin excess of 500 kg/cm² under high shear conditions. The high shearresults in dispersion of the olefin gas in micron or submicron-sizedbubbles. In some embodiments, the resultant dispersion has an averagebubble size less than about 1.5 μm. Accordingly, the dispersion exitingHSD 140 via line 118 comprises micron and/or submicron-sized gasbubbles. In some embodiments, the mean bubble size is in the range ofabout 0.4 μm to about 1.5 μm. In some embodiments, the mean bubble sizeis less than about 400 nm, and may be about 100 nm in some cases. Inmany embodiments, the microbubble dispersion is able to remain dispersedat atmospheric pressure for at least 15 minutes.

Once dispersed, the resulting olefin/chlorinating agent/water dispersionexits HSD 140 via line 118 and feeds into vessel 110, as illustrated inFIG. 1. As a result of the intimate mixing of the reactants prior toentering vessel 110, a significant portion of the chemical reaction maytake place in HSD 140, with or without the presence of a catalyst.Accordingly, in some embodiments, reactor/vessel 110 may be usedprimarily for heating and separation of volatile reaction products fromthe chlorohydrin product. Alternatively, or additionally, vessel 110 mayserve as a primary reaction vessel where most of the chlorohydrinproduct is produced. Vessel/reactor 110 may be operated in eithercontinuous or semi-continuous flow mode, or it may be operated in batchmode. The contents of vessel 110 may be maintained at a specifiedreaction temperature using heating and/or cooling capabilities (e.g.,cooling coils) and temperature measurement instrumentation. Pressure inthe vessel may be monitored using suitable pressure measurementinstrumentation, and the level of reactants in the vessel may becontrolled using a level regulator (not shown), employing techniquesthat are known to those of skill in the art. The contents are stirredcontinuously or semi-continuously.

Embodiments of the process generally comprise contacting a chlorinesource with an olefin under conditions sufficient to form achlorohydrin. The chlorine source or chlorinating agent may be anysource of chlorine that is capable of forming a chlorinating species.Examples of such chlorine sources are chlorine (Cl₂), hypochlorous acid(HOCl), chlorine monoxide (Cl₂O), or a hypochlorite (—OCl) of an alkalimetal or alkaline earth metal. The chlorine source is preferably Cl₂,more preferably, Cl₂ gas. The chlorinating species may also comprise atleast one compound selected from the group consisting of hypochlorousacid, alkali metal hypohalites, and alkaline earth metal hypohalites.Preferably, chlorine source or chlorinating agent is in an aqueous orliquid phase. In on embodiment, the chlorine source or agent may bedissolved in water.

In an embodiment, the method may comprise contacting the chlorinatingspecies with at least one unsaturated organic compound containing from 2to 10 carbon atoms, preferably 2 to 8 carbons, and more preferably 2 to6 carbons. The unsaturated organic compound may be selected from thegroup consisting of substituted and unsubstituted olefins and cyclicolefins. The substituted olefins may have substituents selected from thegroup consisting of an alkyl radical, a phenyl radical and analkylphenyl radical (i.e. tolyl, xylyl or ethylphenyl). Each of theseradicals may also be unsubstituted or substituted. When substituted, thesubstituents preferably comprise halides, hydroxides, or inertsubstituents. By “inert substituents” it is meant that the substituentsdo not interfere with the process of this invention. Any suitableunsaturated compound containing from 2 to 10 carbon atoms and meetingthe criteria specified above can be used in the process of the inventionto prepare the corresponding chlorohydrin. Such unsaturated organiccompounds include, but are not limited to, ethylene, propylene,butylene, hexene, cyclohexene, cyclopentene, cyclooctene, and mixturesthereof. Examples of substituted olefins include allyl alcohol, allylchloride, styrene, 4-bromo-1-butene, 3-chloro-1-butene,3-chloro-2-methylpropene, 1-hexene-3-ol, 3-butene-2-ol, 3-pentene-2-ol,1 -octene-3-ol, and mixtures thereof.

The reaction may proceed under temperature and pressure conditionscommonly employed in such catalytic chlorination reactions. Generally,embodiments of the process are carried out by reacting a olefincontaining about 1 to about 10 carbon atoms with a chlorine source toobtain the desired chlorohydrin reaction product. More specifically, thechlorination reaction in reactor 110 may be conducted with mixing and ata temperature between 0° C. to 100° C. and pressure between ambient to100 psig (791 kPa). Preferably, the temperature is from 20° C. to 80°C., more preferably from 40° C. to 60° C.

Multiple Pass Operation. In the embodiment shown in FIG. 1, the systemis configured for single pass operation, wherein the output from vessel110 goes directly to further processing for recovery of chlorohydrinproduct. In some embodiments it may be desirable to pass the contents ofvessel 110, or a liquid fraction containing unreacted olefin, throughHSD 140 during a second pass. In this case, line 116 is connected toline 121 via dotted line 120, and the recycle stream from vessel 110 ispumped by pump 105 into line 113 and thence into HSD 140. Additionalolefin gas may be injected via line 122 into line 113, or it may beadded directly into the high shear device (not shown).

Multiple High shear Devices. In some embodiments, two or more high sheardevices like HSD 140, or configured differently, are aligned in series,and are used to further enhance the reaction. Their operation may be ineither batch or continuous mode. In some instances in which a singlepass or “once through” process is desired, the use of multiple highshear devices in series may also be advantageous. In some embodimentswhere multiple high shear devices are operated in series, vessel 110 maybe omitted. In some embodiments, multiple high shear devices 140 areoperated in parallel, and the outlet dispersions therefrom areintroduced into one or more vessel 110.

While the preferred embodiments of the invention have been shown anddescribed, modifications thereof can be made by one skilled in the artwithout departing from the spirit and teachings of the invention. Theembodiments described and the examples provided herein are exemplaryonly, and are not intended to be limiting. Many variations andmodifications of the invention disclosed herein are possible and arewithin the scope of the invention. Accordingly, the scope of protectionis not limited by the description set out above, but is only limited bythe claims which follow, that scope including all equivalents of thesubject matter of the claims.

The discussion of a reference is not an admission that it is prior artto the present invention, especially any reference that may have apublication date after the priority date of this application. Thedisclosures of all patents, patent applications, and publications citedherein are hereby incorporated herein by reference in their entirety, tothe extent that they provide exemplary, procedural, or other detailssupplementary to those set forth herein.

1-10. (canceled)
 11. A system for production of chlorohydrin comprising;at least one high shear device configured for chlorinating an olefin,said high shear device comprising a rotor and a stator, said rotor andsaid stator are separated by a shear gap in the range of from about 0.02mm to about 5 mm, wherein the shear gap is a minimum distance betweensaid rotor and said stator, and wherein the high shear device is capableof producing a tip speed of the at least one rotor of greater than about23 m/s (4,500 ft/min); a pump configured for delivering a liquid streamcomprising liquid phase to the high shear device; and a vesselconfigured for receiving the dispersion from the high shear device andfor maintaining a predetermined pressure and temperature.
 12. The systemof claim 11 wherein the high shear device comprises two or more rotorsand two or more stators.
 13. The system of claim 11 wherein said highshear device comprises a rotor tip and said device is configured foroperating at a flow rate of at least 300 L/h at a tip speed of at leastabout 23 m/sec.
 14. The system of claim 11 wherein said high sheardevice is configured to provide an energy expenditure greater than about1000 W/m³.
 15. The system of claim 11 wherein the at least one highshear device is configured for producing a dispersion of olefin gasbubbles in a liquid phase comprising and a chlorinating agent, whereinthe dispersion has a mean bubble diameter of less than 400 nm.
 16. Thesystem of claim 11 comprising at least two high shear devices.
 17. Thesystem of claim 11 wherein the high shear device has a tip speed ofgreater than about 20 m/s (4000 ft/min).
 18. The system of claim 11further comprising a fixed bed reactor, the reactor comprising achlorination catalyst.
 19. The system of claim 11 wherein the high sheardevice comprises at least two generators.
 20. The system of claim 19wherein the shear rate provided by one generator is greater than theshear rate provided by another generator.